Vehicles, including but not limited to recreational vehicles (“RVs”, in the United States and “Caravans” in Europe), tractor trailers, airplanes, boats, trains and the like, often incorporate refrigerators for the comfort and convenience of the occupants. For example, recreational vehicle campers often find it convenient, or even necessary, to refrigerate food, drinks, and medicine during their journal and while at their campsites. While many prepared camp sites in parks and commercial campgrounds provide for electrical outlets, many do not. Moreover, many highly desirable camping locations exist outside of these prepared sites. Thus, a popular solution has been to equip the recreational vehicle with an absorption refrigerator.
Absorption refrigerators employ heat to vaporize the coolant—water mixture (typically ammonia-water) thereby driving the refrigeration loop in a manner well known to those skilled in the art. Popular heat sources include electrical heaters and fuel burners. Further, the fuel burners typically employ propane which is readily available at camping supply stores, barbeque supply stores, and numerous gas stations. Though, any liquid or gaseous fuel would work well and be controllable through simple, automated control systems.
In practice, the present inventor found that various problems might interfere with cooling the interior volume of the refrigerator while still leaving the heat source driving the refrigeration system. Since it is desirable to conserve energy, the present inventor recognized a need to turn off the heat source when refrigeration is no longer practicable.